Analysis of internal flow and cavitation characteristics for a mixed-flow pump with various blade thickness effects

In this study, a numerical analysis was carried out to investigate the effects of blade thickness on hydraulic performance and cavitation phenomenon of a mixed-flow pump. The three-dimensional Reynolds-averaged Navier-Stokes equation, which was discretized using the finite volume method, was applied to solve a steady-state analysis. For cavitation analysis, the Rayleigh-Plesset equation was applied to calculate the transition between liquid and vapor phases. The hydraulic performance of a mixed-flow pump changes depending on the blade thickness and was systematically analyzed under various operating conditions. Blade thickness was defined as a blockage, and the cavitation coefficient was considered to express the suction performance. Cavitation characteristics were analyzed for each blockage in relation to the vapor volume fraction. The amount and pattern of vapor were different for each blade thickness case. Furthermore, in this paper, detailed flow analyses that consider the angle of incidence are presented and discussed. To verify the numerical analysis results, an experimental test was conducted at specific points.